1. Field of the Invention
The present invention relates to the technical field of agricultural machinery and in particular to cutting machines.
The invention relates to an agricultural machine comprising:
a bearing structure,
a first shaft and a first wheel,
a second shaft and a second wheel, the axis of rotation of this second shaft being at least approximately parallel to the axis of rotation of the first shaft,
at least one endless transmission member wrapped around said wheels,
a first bearing guiding the rotation of the first shaft and fixed to the bearing structure,
a second bearing guiding the rotation of the second shaft and connected to the bearing structure by means of an articulation, the geometric axis of which is at least approximately parallel to the axis of rotation of the second shaft,
a device for the mounting/disassembly and automatic tension adjustment of said endless transmission member(s) comprising, in particular, at least one spiral spring and acting on the second bearing so as to tension said endless transmission member(s).
2. Discussion of the Background
An agricultural machine such as this is known from the state of the art (Patent FR 2 317 869) and broadly speaking comprises a cutter bar intended to cut a standing product, and an endless windrowing belt located at one of the ends of said cutter bar and intended to convey product cut by said cutter bar. This windrowing belt is wrapped around two guide cylinders with approximately parallel longitudinal axes. The tension in the endless windrowing belt is adjustable by means of a positioning mechanism which allows one of the two cylinders to move. For this purpose, the positioning mechanism comprises a pivoting lever which at one of its ends supports one of said guide cylinders and which at the other of its ends is subject to the action of a spring, the pressure of which can be adjusted using a nut. This spring is essentially intended to brake the nut and damp out any jerk in the endless windrowing belt.
To ensure good tension in the windrowing belt, the operator acts on the nut, which acts on the spring, which itself tends to cause the pivoting lever to pivot in such a way as to tension the endless windrowing belt. An adjustment device such as this requires frequent and regular checking of the tension in the endless windrowing belt, to ensure that the latter operates correctly.
Also known from the state of the art (DE 27 07 030) is an agricultural machine comprising two pulleys around which a belt equipped with cutting elements is wrapped. One of the pulleys is connected to a chassis by means of a first connection whereas the other pulley is connected to a mobile assembly by means of a second connection, the latter being guided in said chassis. Between the chassis and the mobile assembly there are elastic washers which are intended to move the two pulleys apart so as to tension the belt. This agricultural machine also has a drawback. Specifically, when the operator wishes to remove the belt, he has to bring the two pulleys together, this being an operation which is complicated because there is no device provided to allow such an operation to be performed.
The object of the present invention aims to overcome the drawbacks of the state of the art.
The object of the present invention therefore aims to produce a cutting machine in which the transmission device requires a minimum amount of maintenance allowing quick intervention on the part of the operator as required for changing worn parts, for example, while at the same time guaranteeing that said transmission device will operate correctly within its limits of use.
Another object of the present invention aims to produce a cutting machine in which the transmission device is simple and inexpensive.
To this end, the objects of the present invention are achieved with the aid of a method for the mounting/disassembly and automatic tension adjustment of one (or more) endless transmission member(s) of an agricultural machine equipped with a bearing structure, which agricultural machine comprises:
a first shaft and a first wheel,
a second shaft and a second wheel, the axis of rotation of the second shaft being at least approximately parallel to the axis of rotation of the first shaft,
said endless transmission member(s) wrapped around said wheels,
a first bearing guiding the rotation of the first shaft and fixed to the bearing structure,
a second bearing guiding the rotation of the second shaft and connected to the bearing structure by means of an articulation, the geometric axis of which is at least approximately parallel to the axis of rotation of the second shaft,
a device for the mounting/disassembly and automatic tension adjustment of said endless transmission member(s) comprising, in particular, at least one spiral spring and acting on the second bearing so as to tension said endless transmission member(s),
wherein:
said device for the mounting/disassembly and automatic tension adjustment of said endless transmission member(s) is fitted in such a way that the action generated by the spiral spring(s) acts on the second bearing with a lever arm with respect to the geometric axis of the articulation connecting the second bearing to the bearing structure which increases once said spiral spring relaxes so that the tension created in the endless transmission member(s) is high enough in the range of permissible values for the elongation of said endless transmission member(s),
the spiral spring(s) is (are) bended so as to bring the second bearing closer to the first bearing by pivoting about the geometric axis of the articulation connecting the second bearing to the bearing structure,
said endless transmission member(s) is (are) mounted or said worn endless transmission member(s) is (are) dismounted, then one (or more) new endless transmission member(s) is (are) remounted,
the spiral spring(s) is (are) released so as to move the second bearing away from the first bearing by pivoting about the geometric axis of the articulation connecting the second bearing to the bearing structure.
The objects of the present invention are also achieved with the aid of a device for the mounting/disassembly and automatic tension adjustment of one (or more) endless transmission member(s) of an agricultural machine equipped with a bearing structure, said device for the mounting/disassembly and automatic tension adjustment of one (or more) endless transmission member(s) moreover comprising:
a first shaft and a first wheel,
a second shaft and a second wheel, the axis of rotation of this second shaft being at least approximately parallel to the axis of rotation of the first shaft,
said endless transmission member(s) wrapped around said wheels,
a first bearing guiding the rotation of the first shaft and fixed to the bearing structure,
a second bearing guiding the rotation of the second shaft and connected to the bearing structure by means of an articulation, the geometric axis of which is at least approximately parallel to the axis of rotation of the second shaft,
said device for the mounting/disassembly and automatic tension adjustment of said endless transmission member(s) comprising, in particular, at least one spiral spring and acting on the second bearing so as to tension said endless transmission member(s),
wherein the device for the mounting/disassembly and automatic tension adjustment of said endless transmission member(s) additionally comprises a telescopic arm comprising a first arm part and a second arm part which are guided in translation one with respect to the other and between which said spiral spring(s) acts (act), the first arm part being connected to the bearing structure and the second arm part being connected to the second bearing at a connection point away from the geometric axis of the articulation connecting the second bearing to the bearing structure, in such a way that said telescopic arm acts on the second bearing with a lever arm which increases as the spiral spring(s) relaxes (relax).
The invention also relates to the following features taken in isolation or in any technically feasible combination:
use is made of one (or more) spiral spring(s) capable of creating tension in the endless transmission member(s), which tension reaches its limit value when said endless transmission member(s) has (have) reached its (their) limit value of elongation;
the telescopic arm additionally comprises a threaded rod, the longitudinal axis of which runs parallel to the longitudinal axis of the telescopic arm, said threaded rod being screwed into one of said arm parts, while the other arm part is guided in translation on said threaded rod along the longitudinal axis thereof, a stop limiting the translational movement of the latter arm part;
said stop is fitted on the threaded rod;
there is another stop on the threaded rod which limits the extent to which the threaded rod can be unscrewed from the arm part into which it is screwed;
said other stop is removable;
the threaded rod is guided in the arm part into which it is screwed, by means of a long guide;
the threaded rod is screwed into the arm part connected to the second bearing;
the telescopic arm is connected to the second bearing by means of an articulation;
the geometric axis of said articulation is at least approximately parallel to the axis of rotation of the second shaft;
the telescopic arm is connected to the bearing structure by means of a pivoting link;
the telescopic arm is connected to the pivoting link by means of an articulation at least approximately parallel to the axis of rotation of the second shaft and said pivoting link is connected to the bearing structure by means of an articulation at least approximately parallel to said axis of rotation of said second shaft;
the pivoting link acts on at least one additional bearing forming part of an endless transmission so as to automatically adjust the tension in the endless transmission member(s) of said endless transmission;
the spiral spring(s) consists (consist) of one (or more) compression spring(s) and the telescopic arm acts on the second bearing by extension;
said endless transmission member(s) consists (consist) of one (or more) belt(s), said first wheel and said second wheel being pulleys.
The present invention also relates to cutting machines, preferably mowers which may or may not be fitted with members for treating the mown product.